Unlike a mastectomy, which removes the entire breast, breast-conserving surgery removes only the affected breast tissue, allowing patients to continue to radiation therapy on an intact breast. Yale was one of the first facilities in the country to offer this effective combination of treatments. Our physicians also perform radiation following mastectomy, and radiation for treatment of metastasis, or for cancer that has spread. To deliver radiation for breast cancer, we use a variety of novel treatments, including conventional external beam radiation, intensity-modulated radiation therapy (IMRT), deep inspiration breath hold (DIBH), and partial breast irradiation. We also offer hypo-fractionated breast radiation, a new treatment that reduces the duration of rational therapy, with fewer side effects.